The present inventors recently characterized a genic male-sterile mutant of soybean: 83(6) Am. J. Bot. 42, abstract 121(1996); Jin et al., 10 Sex Plant Reprod. 13 (1997). Microscopic analysis of the mutant showed the callose encasement of the microspores was retained at an inappropriate developmental stage. The persistent callose encasement resulted in no release, and subsequent degeneration of the microspores. Other results in these publications showed that callase, the enzyme which is responsible for digestion of the callose wall, was inactive. The reason for the inactivity was not elucidated at that time.
Other publications by the present inventors identified the callase as a .beta.-1,3-glucanase. Abstract P14, Genetics Society of Canada (June 1997); 114(3) Plant Physiology 172, abstract 842 (June 1997); 84(6) Am. J. Bot. 63, abstract 182 (June 1997).
Soybean .beta.-1,3-glucanases have been cloned in the past. For example, U.S. Pat. No. 5,477,001 disclosed cloned .beta.-1,3- glucanases from soybean. The gene products are implicated in disease resistance. No disclosure of the involvement of .beta.-1,3- glucanases as a callase is described in the patent. Non-soybean glucanases, such as those described in U.S. Pat. No. 5,554,743 describe .beta.-1,3-glucanases involved in cell wall polysaccharide degradation.
A search of the National Institutes of Health BLAST database disclosed a line of soybean "Glycine max cv. Century 84" with cloned .beta.-1,3-glucanases. None of the sequences found were identical to the presently-claimed sequences. The following is a table of the results of the search.
______________________________________ SEQ ID NO CLOSEST HOMOLOGY REFERENCE ______________________________________ 1 85% (soybean glucanase) U.S. Pat. No. 5477001, Seq 8; same as WO9413790, Seq 15 2 98% (soybean endoglucanase) none available 3 91% (Century 84) 26 Crop Science 199 (1986) 4 97% (soybean glucanase) U.S. Pat. No. 5477001, Seq 8; same as WO9413790, Seq 15 5 76% (Century 84) 26 Crop Science 199 (1986) 6 91% (Century 84) 26 Crop Science 199 (1986) 7 54% (unknown) U.S. Pat. No. 5614395, Seq 13; same as WO9413790, Seq 15 8 85% (soybean glucanase) U.S. Pat. No. 5477001, Seq Id 8; same as WO9413790, Seq 15 9 75% (Century 84) 26 Crop Science 199 (1986) 10 97% (Century 84) 26 Crop Science 199 (1986) 11 76% (Century 84) 26 Crop Science 199 (1986) 12 96% (soybean glucanase) U.S. Pat. No. 5477001, Seq Id 8; same as WO9413790, Seq 15 ______________________________________
The U.S. Pat. No. 5,477,001 does not disclose or suggest the present invention, because the sequences described herein are not disclosed. Moreover, the emphasis in the U.S. Pat. No. 5,477,001 is the use of a particular soybean glucanase to resist plant diseases. In certain aspects of the present invention, the focus is on the elimination of active soybean glucanases; the U.S. Pat. No. 5,477,001 therefore teaches away from those aspects of the present invention.
Century 84 is a line of soybean which was released jointly by the Ohio Agricultural Research and Development Center, The Ohio State University and the USDA which contained over-expressed glucanase for the purpose of disease resistance. Registration Number 188,26 Crop Science 199 (1989).
Citation of the above documents is not intended as an admission that any of the foregoing is pertinent prior art. For example, in some instances above, the publication was less than one year before the filing date of this patent application. All statements as to the date or representation as to the contents of these documents is based on subjective characterization of information available to the applicant at the time of filing, and does not constitute an admission as to the accuracy of the dates or contents of these documents.